Electric soldering iron



OQL 13, 1936. v BOHALL ET AL 2,056,951

ELECTRIC SOLDERING IRON Filed Sept. s, 1953 INVENTORS Ads-4.90M Bo/m LLTHEODORl/JS BAIYLE) Patented Oct. 13, 1935 UNITED STATES PATENT OFFICEELECTRIC SOLDERING IRON Application September 5, 1933, Serial No.688,088

Claims.

This invention relates to electric soldering tools and has for itsobject improvements in the construction of such devices whereby the toolis more eifective, safe, handier in use, and more portable.

5. Other features and advantages will appear in the followingdescription and accompanying drawing.

In the drawing Fig. l is a side elevation of our improved electric toolin extended position and with a folding supporting leg turned outward.

Fig. 2 is a plan view of the tool in collapsed condition as for placingin the tool kit.

Fig. 3 is an enlarged longitudinal section of the forward half of theiron showing the internal construction thereof.

Fig. 4 is a cross section of Fig. 3 as seen from the line 4-4 thereof.

Fig. 5 is an enlarged cross section of Fig. l as seen from the line 5-5thereof.

Fig. 6 is a side view of the extended tool similar to that of Fig. l butshowing the folding leg attached to the heating element instead of tothe handle.

Fig. 7 is an enlarged sectional view of the construction at the heatingelement terminals.

In further detail, the'improved construction comprises a tubular metalhandle I slotted along one side as at 2 and slidable within the tube lis a block 3 from which extends a tubular metal so sleeve 4, 5, at theouter enlarged end of which is a conical chuck 6 of metal and throughwhich extends a cylindrical soldering copper or bit 1, while pivoted at8 to the outside of the outside of the forward end of the handle I iscurved sheet 35 metal leg Badapted to rigidly support the iron inslanted position from the floor l0, table, or other supporting surfaceas shown in full lines in Fig. l, or fold up to overlap and embrace thesides of the tubular handle I as indicated by the dotted 40 lines 9 inFig. 1. This leg may optionally be attached to the sleeve 5 as shown inFig. 6 at 9" if desired;

The sliding block 3 within the tubular handle is made of electricallyinsulating material such as porcelain or bakelite and is secured bymeans of a screw. ll within a short length of metal tube [2 which fitsslidably within the hollow handle I and is moved therealong and lockedat any position by means -of a thumb screw l3 passing 5() through thehandle slot 2 and threads through one side of the sliding tube l2 aswell as through an inner insulating tube l4 and the neck of its metalclosing cap which forms a space 16 between the inner end of insulatingblock 3 and cap l5. 7

Cap [5 is centrally apertured to pass a heavily insulated cable ll,the-two wires l8, [9 of which pass through holes in a guarded lug 20formed on the inner end of block 3 and are secured respectively tobinding screws 21, 22 which also take the lead wires 23, 24 which extendthrough porcelain or other insulators 25 within the metal sleeve 4 tosupply current to the heating element proper.

Sleeve 4 fits tightly into an axial hole in block 3 and is secured inplace by a countersunk screw 26 and the insulator 25 is of less diameterthan the sleeve 4 so as to preserve an air space 36 around the insulatoras shown. At the point where the sleeve is enlarged to the largerdiameter 5 the lead wires 23 and 24 are welded to larger wires 21, 28which pass into an insulating block or cement plug 34 and turn outwardlywith their ends threaded and fitted with thin fiat nuts 29, 30 wherethey attach to the terminals of the heating element 3i which consists ofa resistance coil Wound over mica or other insulating sheets 32supported on the outside of a metal tube 33 (preferably brass) which issecured to and extends forwardly from the insulating plug 34. Theheating coil is covered outside by a plaster of insulating cement toform a hard cylinder of lesser diameter than the inside of enlargedsleeve 5 so as to preserve an air space 35 therearound which is ventedtogether with the space 36 through a series of holes 31 in the smallerportion 4 of the sleeve.

The forward end of metal tube 33 passes tightly into a counter bore inthe chuck and sleeve 5 extends into a recess formed in the chuck, allparts at this point being held from possibility of displacement by meansof a set screw 39 which passes through the parts mentioned and impingesagainst the copper bit 7 which extends through the chuck and the brasssleeve 33 around which the heating coil is wound. Thus the bit may beadjusted to various points of projection into the hollow heating elementand secured with the set screw so as to get any heating effect desired.

When through using the soldering iron the leg 9 is folded up against thetubular handle I and the telescopic portion 5 and its bit 1 are slidwithin the hollow handle by loosening and moving thumb screw I3 alongthe slot 2 and giving it a slight turn at the end of the slot to lock itso as to prevent the still hot bit from coming out of its protectivehandle. The sleeve 5 and bit 1, being considerably smaller in diameterthan the inside of the handle, are ventilated for quick cooling and willnot overheat the handle, so that it issafe to at once replace thesoldering iron in the tool kit. The folding leg 9, it will be noticedhas two outwardly turned toes 4B, which serve as striking corners too-utfold it.

A feature of importance is the support of the heating coil on a brass orother non-magnetizable metal tube into which the solid copper bit slidesas this has been found to do away with pitting of the bit whichsometimes takes place in electric soldering irons where iron or steel isused in corresponding parts.

Attention is also directed to the construction of our device at theterminals of the resistance coil, or heating element 3|, as best showninFig'. 7.

The metal tube 33 or core of the. tool in which the bit is fitted, isprovided with openings adjacent the inner end of the bit appreciablylarger than the large wires 21, 28, through which openings the ends ofwires 21, '28 extend. Nuts 28,

29 are a trifle smaller than these openings and the ends of theresistance coil are secured around the ends of these wires respectivelybetween the nuts and a washer, the washer also being'slightly smallerthan the openings in the tube 33. The mica sheet 32 extends to the innerend of the tube 33 and is provided with openings aligned over theopenings in the tube 33, and which openings in the mica sheet aresubstantially the same diameter as the wires 21, 28. Thus when the nuts29, 3'0 are tightened, the mica sheet is forced over the edges of theholes respectively in the metal tube 33, as indicated in Fig.effectually insulating the edges of the holes in tube from the wires andbringing all of the wire of the resistance coil directly in contact withthe metal tube 33, save for the mica, from the terminals thereof.

By the above construction the heat from the resistance coil istransmitted by conduction all along its length to the metal tube whichholds the bit, thus none of the heat is carried into the handle and thecoil will last indefinitely since none of its length is exposed to thedetrimental effects from excessive heating as in those tools 'where alength of the heating coil finds no material to conduct the heat awayfrom it. Also by our construction, a lower wattage can be used with thesame results as in others in which higher wattage is necessary. This isbecause all of the 'heat of the coil goes to the core in which the bitis fitted, and from thence directly into the length of the bit that iswithin the core.

7 Furthermore, by the above construction, it is possible to reduce thediameter of the shell 5 to the point where it will slide into the handle1 without making the handle so large that it is unwieldy. To ourknowledge no one has before successfully attached the terminals of theresistance coil to the lead-in power wires at the point adjacent theinner end of the bit, and the importance of the feature in ourcollapsible iron is particularly important in that it preventsconductionof the heat into the handle therebypermitting the tool to be immediatelytossed into a tool kit without danger when the tool is collapsed afterusing.

Having thus described our improved electric soldering tool, what weclaim is:

1. An electric soldering tool comprising a tubular handle, an electricheating element, a soldering bit extending from within said element,means mounting the element and bit for sliding within the handle, and aleg foldably carried by the assemblage adapted for supporting the toolwith heated bit elevated when the element and bit are in extendedposition out of the handle and to be enclosed within the handle when theelement and bit are retracted into the handle.

2. An electric soldering tool comprising a tubular handle, a blockslidable within the handle and provided with electric terminalconnections, power wires extending into the handle from one end thereofconnected tosaid terminal connections, a tubular sleeve secured at oneend within the block extending out of the same and handle, a tubularelectric heating element within said .sleeve with terminal wiresextending to the terminal connections of said block, and a soldering bitextending into the outer end of the tubular electric heating element, achuck at the outer end of said tubular electric heating element throughwhich said bit passes, and a screw extending through the chuck impingingthe bit.

' .3. In asoldering tool provided with a handle, a tubular sleevemounted at one end within said handle and projecting outwardlytherefrom, a tubular heating element within said tubular sleeve at theend thereof remote from the-handle, a soldering bit extending into saidtubular heating element, power wires connected to said heating elementat a point within the projecting sleeve adjacent the inner end of saidbit, the handle of said tool being hollow and themountingof the tubularsleeve being of insulation material and slidable within the handlewhereby the sleeve and bit may be withdrawn into the handle.

4. An electric soldering tool comprising a tubular handle, a blockwholly enclosed within said tubular handle and 'slidably mounted thereinfor sliding substantially from end to end thereof, an elongated tubularmember secured at its inner end to said block for movement therewith,said tubular member supporting a heating element and bit in its outerend with the bit projecting from said heating element, said tubularhandle adapted to fullyenclose the tubular member and bit when the blockis at one end of the handle, and substantially the full length of thetubular member being exposed and projecting from the opposite end of thehandle when the block is moved to saidopposite end, the overall lengthof said block, tubular member and bit being substantially equal totheoverall length of the handle whereby the length of the complete toolwhen the block, tubular member .and bit are enclosed within the handleis substantially half the length of the length of the handle, tool andbit when extended, said block being adapted to support the bit-andheating element-spaced from the sides of the handle when the bit andheating element are retracted into the handle.

5. In a construction as defined in claim 4, a leg foldably carried bythe tool arranged and adapted for supporting the heated bit elevatedwhen the leg is extended and to fold against a side of the tool andwithin the longitudinal dimensions of the tool when the tubular memberincluding the bit is retracted into the tubular handle.

6. An electric soldering tool comprising an electric heating element,asolderingbit mounted therein adapted'to be heated by the element andelectrical conductors connected to the heating element for supplyingelectricity thereto, a handle, means mounting said bit and heatingelement including the connections between the electrical conductors andheating element for sliding the bit, heating element and electricalconnections from a position wholly enclosed within the handle to aposition with the bit and'hea'ting element rigidly supported relative tothe handle and extended therefrom whereby the length of the tool whencollapsed is less than the length of the tool when extended by adistance substantially that of the exposed length of the bit and elementwhen the same are extended from the handle, said bit being substantiallyspaced from the inner sides of the handle when retracted thereinto.

7. An electrical soldering tool comprising a tubular heating element, asoldering bit mounted therein and projecting therefrom in axialalignment therewith, electrical conductors connecting with said heatingelement, said heating element, soldering bit and electrical conductorsall being rigidly secured together, a tubular handle adapted to fullyenclose the heating element and soldering bit and the connectionsbetween said electrical conductors and heating element with theelectrical conductors extending from one end of the handle, meansslidably supporting said heating element and bit within the handle inaxial alignment therewith and with the bit spaced from the inner sidesof the handle for movement of the bit longitudinally of the handle forexposing said bit from an end oi the handle, and means adjacent a sideof the handle for sliding said means longitudinally thereof.

8. An electric soldering tool comprising an elongated tubular handle, ablock slidable within the handle longitudinally thereof provided withelectrical terminal connections, power wires extending into the handleconnected to said electrical connections, an electrical heating elementrigidly secured to said block and a soldering bit projecting from withinsaid electrical heating element, electrical conductors connecting saidheating element and electrical terminal connections, said block beingwholly enclosed within said handle and the heating element and bit beingadapted to be wholly retracted to within the handle upon sliding saidblock toward one end thereof and to be exposed upon sliding the blocktoward the opposite end, releasable means for rigidly securing saidblock against movement relative to the handle at opposite ends 01' itslongitudinal movement within the handle, said bit being substantiallyspaced from the inner sides of the handle when retracted thereinto andmeans insulating said electrical conductors and electrical terminalconnectors from the handle.

9. An electric soldering tool comprising an elongated tubular handle, anelectric heating element, a soldering bit extending from within saidelement, means wholly enclosed within said handle and slidablelongitudinally thereof mounting the element and bit for supporting thebit extended from the handle and for sliding the bit and element to aposition wholly within the handle with the bit spaced from the walls ofthe handle, said handle being provided with a slot along one sideextending longitudinally thereof, locking means extending through saidslot adapted to serve as a finger-grip for sliding said meanslongitudinally of the handle and for positively locking said means atany desired position relative to the length of the handle whereby saidbit is adapted to be rigidly secured against movement relative to thehandle at any desired point of extension therefrom, electricalconductors extending from said handle and connecting with said elementfor movement with the means mounting the bit and element and the meansmounting the bit and element including the electrical conductors fromthe handle.

10. In a construction as defined in claim 9, said locking meansincluding a threaded bolt secured at one end to the means mounting theelement and bit, a thumb nut on said bolt outwardly of said slot adaptedto tightly engage the edges of the slot between the nut and meansmounting the bit and element upon turning the nut.

NELSON E. BOHALL. THEODORUS S. BAILEY.

